Bobbi Kristina Brown engaged to 'adopted brother' Nick Gordon?

Brown, who lost her mother last month, was recently photographed allegedly kissing and holding hands with 22-year-old Nick Gordon, who is not biologically related to her but was unofficially adopted by Houston when he was 12 years old and lived with the family ever since.

Gordon has denied that he and Brown are dating, telling ABC News: "We're just close - just going through her mom's passing and grieving together."

He also promised on his Twitter account to speak to "you loyal ones" in due course, adding: "[If] it was about money.... Do you know how many interviews I was asked to give. I will remain loyal. And keep our memories to myself."

Gordon had earlier written: "Yea (sic) we got a little closer and what!!!"

A source told Star magazine of the rumored engagement: "Nick proposed to Krissy on March 10, and she said yes. Krissy said Nick is the only person she trusts in the world. They have a very deep connection."

Another insider claimed: "Krissy said Nick is the only person she trusts in the world. He's always been extremely protective of Kristina. [They] have blurred the boundaries between a platonic relationship and a romantic one for some time. They've even been sleeping in the same bed!"

However, a third source has alleged that Gordon has only proposed because Bobbi is about to inherit Houston's fortune.

"Nick is getting her at her most vulnerable," they claimed. "If he really loved her, he'd back off the engagement and just be her friend."

Gordon's grandmother Maxine is quoted as saying: "Nick took care of Whitney and Kristina. He's always been extremely protective of Kristina."